Field of the Invention
This invention relates to an axle suspension mounting system and more particularly to a lift axle suspension mounting system wherein the lift axle suspension assembly is secured to the frame of a truck between the tandem axles and the cab of the truck. The lift axle suspension assembly may also be mounted on the rearward end of the frame rearwardly of the tandem axles. The lift axle suspension assembly is pivotally movable with respect to the vehicle between a first position in which the wheels of the lift axle are elevated and a second position in which the wheels of the lift axle engage the ground. More particularly, the lift axle suspension mounting system of this invention is designed to fit truck frames having varying dimensions. Even more particularly, the lift axle suspension mounting system of this invention represents an improvement over assignee's earlier lift axle suspension mounting system described and shown in U.S. Pat. No. 6,316,993 B1. Although the axle suspension system of this invention is well suited for use with a lift axle, it is also well suited for use with auxiliary axles which are not of the lift type.
Description of the Related Art
Lift axle assemblies have been used for many years on work vehicles such as transit concrete mixers, gravel trucks, etc. The lift axle assemblies of the prior art permit the vehicle to carry more weight while still meeting the regulations governing the weight which the vehicles can legally carry over federal and state highways. Most of the prior art lift axle assemblies are pivotally movable with respect to the frame of the vehicle so that the wheels of the lift axle assembly may be pivotally moved from a ground engaging position to an elevated position.
Assignee's lift axle suspension mounting system described and shown in U.S. Pat. No. 6,311,993 represented a significant advance and improvement in the lift axle suspension mounting systems of the prior art. The instant invention represents a further advance in the art in that it is more convenient to assemble than the system of the '993 patent.